Rosiane de Lourdes Silva de Lima

Redistribuição de nutrientes em folhas de pinhão-manso entre estádios fenológicos

Nutrient redistribution from mature leaves to growing structures is an important process in plant physiology. Each nutrient is redistributed in a different rate and time. This study aimed to quantify redistribution of macronutriens and minor nutrients in Jatropha curcas leaves through five phenological phases (expanding leaf, young leaf, mature leaf, senescing leaf, and dry leaf). It was observed that the nutrients P, K, Cu, and Zn are intensively redistributed from older to younger jatropha leaves, while N, Ca, Mg, Fe, and Mn are poorly redistributed. Leaf senescence causes a loss of the nutrients that are not redistributed because they will need to be re-absorbed for supporting the growth of new structures in the plant.

Posição da folha e estádio fenológico do ramo para análise foliar do pinhão-manso

ABSTRACT Leaf analysis is an important tool for prediction of nutritional disorders and evaluation of nutritionalstatus of plants. This procedure only can be effective if samples are standardized regarding leaf positionand phenological stage of the branch. This study had the objective of defining the most appropriate leafposition and type of branch for nutritional diagnosis of Jatropha plants. A factorial combination of fiveleaf positions (1 st , 2 nd , 3 rd , 5 th , and 10 node from apex to base) and two types of branch (vegetative andflowering) was adopted in a completely randomized design with four replications. Each leaf sample wascollected in 4 secondary branches of 20 plants in the flowering phase. Leaves in the position 2 and 3 arethe most adequate for analyzing N, P, K, S, Cu, Fe, Mn, and Zn, because they present mean values morestable when compared to the other studied positions. Leaves in the position 5 and 10 are more adequatefor analyzing Ca and Mg. The phenological stage of the branch does not influence nutrient content,except of Cu and Fe.

Comprimento das estacas e parte do ramo para formação de mudas de pinhão-manso

Jatropha curcas is traditionally propagated by seed. However, in several situations the vegetative propagation is an important alternative and its technology needs to be developed. The objective of this study was to evaluate how the length and the portion of the branch from where the cuttings are extracted, influence the rooting and growth capacity of Jatropha cuttings. The treatments were arranged in a 3 x 4 factorial design, with three cutting positions (apical, middle and basal) and four cutting lengths (10, 15, 20, and 25 cm). A completely randomized design with four replications and ten cuttings per plot was adopted. At 70 days after planting, the cuttings were evaluated for the number of sprouts and branches, branch length, number of leaves, leaf area, number of roots, and dry mass of shoots and roots. The position from where the cuttings are extracted (apical, middle or basal) did not influence its capacity for rooting and the growth of the seedlings. The cutting length influences the initial growth, and the best growth was obtained in cuttings of around 22 cm.

Tolerância de mamoneira ao herbicida pendimethalin em solos com diferentes capacidades de adsorção

The castor bean is a species of slow initial growth. The absence of registered herbicides for this crop is still a limiting factor for its expansion. The aim of this study was to evaluate the castor bean tolerance to the herbicide pendimethalin in soils with different adsorption capacities. The experiment was conducted under greenhouse conditions in a completely randomized design with five replications and consisted of a factorial combination of eight doses of the herbicide pendimethalin applied as pre-emergence (0; 187,5; 375; 750; 1500; 3000; 6000 and 12000 g ha-1 i.a.), and four types of substrate (clay loam, sandy clay loam, sandy loam and sandy soil). At 22 days after sowing the variables: plant height, leaf area, fresh and dry mass of shoots, root system volume and dry weight were determined. It was concluded that the dose of the herbicide pendimethalin tolerated by the castor bean is influenced by the adsorption capacity of the soil. The herbicide was found to be very selective to this crop, not causing significant reduction of plant growth at the doses indicated to be used for weed control.

Diagnose foliar da gravioleira (Annona muricata L.): efeito da posição de ramos e folhas

A carencia de informacoes na literatura sobre a amostragem de folhas da gravioleira, particularmente, a definicao da posicao da folha na copa das arvores e das folhas nos ramos ainda e um fator limitante para a diagnose foliar dessa cultura. Objetivando determinar a parte da planta indicada para a amostragem de folhas e a avaliacao do estado nutricional da gravioleira conduziu-se um experimento no Campo Experimental da Embrapa Agroindustria Tropical, em Pacajus (CE), no periodo de marco a abril de 2003. Colheram-se folhas de tres posicoes da copa (terco superior, terco medio e terco inferior) e tres posicoes no ramo (folhas da parte apical, mediana e basal) e determinaram-se os teores de P, K, Ca, Mg, S, Fe, Cu, Zn e Mn. Os resultados permitem sugerir que os teores de minerais das folhas da parte mediana da copa das arvores e na posicao mediana do ramo refletem melhor o estado nutricional da frutifera.

Variação sazonal de micronutrientes em folhas de aceroleira (Malpighia emarginata DC.)

Os teores de micronutrientes nas folhas necessarios para obter boa produtividade e qualidade de frutos de aceroleira (Malpighia emarginata DC.) e sua variacao sazonal sao pouco conhecidas. Para melhor entendimento da dinâmica de absorcao de nutrientes e o desenvolvimento dessa frutifera avaliaram-se teores foliares de Cu, Fe, Mn e Zn, em seis progenies de aceroleira no periodo de dezembro de 1999 a outubro de 2000. O estudo foi conduzido na Embrapa Agroindustria Tropical, em Pacajus, e envolveu 6 progenies (P52, P66, P78, P91, P93 e P97) e 6 epocas de amostragem das folhas (dezembro, fevereiro, abril, junho, agosto e outubro de 2000). A variacao sazonal foi confirmada para os teores de Cu, Fe, Mn e Zn nas folhas, enquanto o Zn nao sofreu alteracao significativa nas progenies consideradas pela pesquisa. Os teores de Cu foram superiores em fevereiro, e os de Fe e Mn em agosto. As progenies apresentaram habilidade diferenciada na manutencao das concentracoes de Cu, Mn e Zn nas folhas. A melhor epoca para amostragem de folhas e diagnostico do estado nutricional foi em outubro, inicio do florescimento das aceroleiras, quando os teores de Cu, Fe, Mn e Zn devem ser superiores a 3, 125, 80 e 15 mg/kg.